Commutator



Nov. 4

1,514,321 W. H. JEFFERY COMMUTATOR l Filed 0C?. 2, i922 Patented Nov. 4, 1924.

UNITED STATES WALTER H. JEFFERY, OF TOLEDO. OHIO.

COIVIMUTATOR.

Application filed October 2, 1922.

T0 @ZZ whome't may con-cern:

Be it known that I, VALTER H. JEFFERY. a citizen of the United States, and a resident vof, Toledo, in the county of Lucas and State of Ohio, have made an invention appert-aining to a Commutator; and T do hereby de-l clare the following to be a full, clear, and exact description of the invention, such as will enable others skilled inthe art to which it appertains to make and use the same, reference beingvhad to the accompanying draw ings, and to the characters of reference marked thereon, which form a part of this specification.

This invention relates more particularly to the manufacture 0f electrical com1nutators of the type having an integral or single piece spool member upon which the segments are built in insulated relation to each other and to the spool and are secured in rigid position thereon by an inward pressing of the spool flanges against the ends of the holding tongues of the segments. The insulator comprising the invention is adapted, however, for use in connection with coml'nutator spools of other types` Tn the manufacture of commutators it has been the practice to place a multiplicity of insulating parts around the spool before mounting and securing the segments thereon, one of the insulating parts customarily comprising a strip of insulating material wound around the spool shank, others comprising short cylindrical members placed around the flanges, and others comprising washer-like members fitted against the inner sides of the spool flanges and being split to enable placing the same around the spool shank. This method of insulating the spool from the segments isnecessarily a slow and tedious one and results in a considerable loss due to breakage of the insulating parts, particularly of the split washer-like members, as well as a considerable loss on account of rejected commutators due to defective insulation, such latter loss frequently running as high as 25% of those tested.

The object of the invention is to insulate the sections of commutators of the class described from their spools in such manner as Serial No. 591,996.

The invention is fully described in the following specification, and while, in its broader aspect, it is capable of enibodimen in numerous fern two embodiments thereof are illustrated in the accompanying cranL ins, in which,-

Figure l is an end elevation of a cominntator embodying the invention. Fig. is a section thereof on the line 2 2 in Fig. l. F 3 is a similar section of the parts of a commutator mounted in initial assembled position with the spool partly in full. l? ig. i is a perspective view of a spool and coacting insulating parts in slightly spaced relation, and Fig. 5 is a similar view with the insulating members separated along diagonal lines.

Referring to the drawings, l designates the commutator segments intended to be mounted around a spool or holding member 2 and having the inner side portions of their opposite ends notched to form, in the present instance, dove-tail tongues or extensions 3 with which the end flanges a of the carrying spool are intended to engage to securely hold the segments in assembled relation on the spool, as is well understood in the art. The spool 2, in the present instance, has its flanges a formed integral therewith, and, in assembling, these flanges are rolled or pressed inward in rigid holding engagement with the ends of the segment tongues 3, as shown in Fig. 2, by the application of inward pressure on the flanges axially of the spool. This method of assembling spools and segments of commutators is old and need not be more specifically described.

The feature of my invention consist-s in the manner of insulating the segments from the spool, and consists in providing a plurality of insulating sections 5, which extend longitudinally of the spool being coextensive therewith and are shaped to substantially conform to both the longitudinal and transverse contours of the portion of the spool which they are intended to embrace. In other words, the insulating sections are circular in cross section to adapt them to fit the circular contour of the spool and each has a central or body portion 6 conforming longitudinally to the straight shank portion of the spool but substantially coextensive in length therewith and terminating at its ends in outwardly turned flange portions 7 which extend out to the outer free edge portions of the flanges 4L and then form extensions 8 which closely embrace the peripheral portions of the spool flanges with which they engage, being disposed in planes parallel to the body portion 6 of the insulation.

n assembling, a sufficient number of the insulating strips 5 are placed around the spool to entirely envelop the same, the adjoining edges of the strips being adapted to meet in close fitting relation, and the segments with the insulated spacing members 9 are then assembled around the insulation andspool in close side edge abutting relation, as shown in Fig. 3. This having been done the ends of the spool, if of the single piece type, are subjected to an inward longitudinal pressure to turn the flanges l with the interposed vportion 'i' of the insulating members against the ends of the segment tongues 3 and to force the end portions S of the insulating members closely against the overhanging end portions of the segments, as shown in Fig. 2, thereby eifectually insulating the segments from the connnutator spool. ln order that the joints between the insulating sections may bev as few as vpossible and thereby reduce to a minimum the possibility of short-circuiting occurring at such points, the insulators preferably oomprise two duplicate sections which may either meet along lines extending longitudinally of the spool in parallel relation to its axis or may meet along lines which are diagonally disposed as shown in Fig. ,4) or angled with respect to the spool axis as shown in Fig. 5, or may be of other forni.

AAn insulation of this character makes a very rapid assembling proposition and is found in actual practice to save approXimately5%A of the time required to assem? ble the multiplicity of insulating parts heretofore employed between the segments and spools of commutatore of this class. lt is also found in practice that the loss from breakage of the insulation parts during the assembling operation is practically entirely eliminated, vwhereas before it ran in the neighborhood of 25% of the insulating parts handled; and furthermore, that the loss due to rejected commutators on account of defective insulation has been reduced from approximately 25% loss to nothing, orin other words, with my insulating means the commutators run approximately y100% perfect so far as insulating defects are concerned.

Having thus described invention, what I claim as new, and desire to secure by Letters Patent, is,-

l. A commutator of the class described having aspool with end flanges, an insulating*V sleeve enclosing the spool and having a central portion fitting into thespool groove and end portions extending radially from the central portion and then axially of the spool over and beyond the end-flanges of the spool, said sleeve comprising two sections which closely abut at their side edges and each of which sections is co-extensive with the length of the sleeve, and a plurality of segments insulated from each other mounted around the sleeve and having portions at their inner sides extending into the circumferential groove of the spool and sleeve, theend flanges of the spool and the embracing portions of the sleeve being in holding engagement with the ends of the inwardly extending portions of the segments.

2. An insulator for the space between the segments and one-piece spool of a commutator, which spool has circumferential end flanges, said insulator comprising a sleeve which at its central portion fits into the spool groove and at its end portions extends out around and beyond the end flanges of the spool longitudinally thereof, the sleeve being in two sections, each of which is c0- extensive` in length with the sleeve and abuts at its side edges the adjacent side edges of the other section to permit assembling of the sleeve on the spoo Y 3. An insulator for the space between the segments and spool of a commutator, such insulator comprising two sections fitting to# gether edge to edge and cooperating to entirely embrace the spool, each section being substantially coextensive with the length of the spool vand having a portion which fits down into the spool groove inengagement with its shank and flanges at its end portions which extend out around the respective spool flanges in embracing relation thereto.

Ll( The method of making commutatore, which consists in providing a spool with radially flanged end portions, mounting two semi-circular insulator sections' in side edge abutting relation around the spool to form an embracing insulating sleeve, which sections are substantially fio-extensive with the length of the spool and are depressed intermediate their ends to t down into the spool groove, mounting a plurality of segments with interposed insulating members circumferentially around Vthe spool and its embracing insulation and then applying inward pressure to the ends of the spool longitudinally thereof to force the spool flanges and coacting portions of the insulating sleeve in end holding engagement with the segments.

In testimony whereof I have hereunto signed my name to this specification.

WALTER H. JEFFERY. 

